Month: October 2008

Escaping down an electrode

Esquire magazine (of all places) has an excellent neuroscience article that discusses the case of Erik Ramsey, a young man with locked-in syndrome whose only hope for communicating with the outside world is a prototype brain computer interface that needs to be implanted directly into his cortex.

Locked-in syndrome is a condition that can occur after certain forms of brain stem stroke. The brain stem acts as the relay station to the peripheral nerves of the body, and hence the control of muscles.

The syndrome is where the person is mentally fine but are physically unable to move any muscle in the body, usually except muscles associated with eyes.

Current methods of communicating typically involve having someone hold up a board with the letters of the alphabet on it. The assistant starts reading off the letters and the locked-in person moves their eye when they arrive at the right letter, and through this method, they slowly spell out sentences.

Famously, Jean-Dominique Bauby created one of the most incredible books ever written, The Diving Bell and the Butterfly, using this method after becoming locked-in.

There is currently a great hope for ‘brain computer interfaces’ that, with a bit of training, might allow locked-in people to communicate through a computer system that translates specific types of neural activity into letters or words.

This is usually described as translating ‘thoughts into words’ but most systems simply link specific patterns of brain activation to specific computer outputs, so as long as they can reliably distinguish between different types of brain activity and reliably produce specific responses the job is done.

In other words, if thinking of sea lions reliably produces an ‘A’ and thinking of a scratch-my-nose action reliably produces a ‘B’ (and so on) this is enough, but the leap between the content of thoughts and the output is not at the level of meaning (where thinking of sea lions would produce ‘sea lions’ as an output).

Interestingly, the training method most of these systems use largely relies on operant conditioning (a type of trial and error learning). We know that we can be conditioned to have certain responses unconsciously, so it may be the case that people using the system don’t ‘feel’ like their thinking about something specific for any particular response. Eventually it just ‘happens’, like driving a car.

The researcher behind the system described in the Esquire article is neuroscientist Phillip Kennedy who was recently featured in an excellent article from the Dana Foundation on his work.

Link to Esquire ‘The Unspeakable Odyssey of the Motionless Boy’ (via FC).
Link to Dana ‘Neural Implant Aims to Restore Speech to the Paralyzed’.

Channelling Colonel Saunders

Shirley Ghostman is a TV psychic whose guests are completely unaware that he’s a spoof and his over-the-top antics are just the creation of comedian Marc Wootton.

In one episode he goes up against well-known psychologist and skeptic Chris French whose dry responses turn out to be funnier than Ghostman’s camp send-up.

French is head of the Anomalistic Psychology Research Unit at Goldsmith’s College in London, which studies the psychological attributes that lead people to believe in the paranormal.

Some of the unit’s publications are online in their archive although you’ll have to wait for one of the best, “The ‘Haunt’ Project: An attempt to build a ‘haunted’ room by manipulating complex electromagnetic fields and infrasound”, as it’s soon to be published in a special edition of the neuropsychology journal Cortex.

Link to Shirtley Ghostman vs a wonderfully sarcastic Chris French.

A bolt from the Blue Brain

Seed Magazine has got video of a great talk by Henry Markham, the director of the Blue Brain Project which is developing the world’s largest simulation of networks of individual neurons in an attempt to understand the large scale dynamics of the brain.

Their ambition is to be able to run a simulation on the scale of the whole human brain within a decade.

If you want a good summary of where the ambitious project is at, Seed recently had an excellent Jonah Lehrer piece on the research that we featured earlier this year.

Markham’s talk is interesting not solely for his take on the project and its aims, but also for the fantastic visualisation he uses to illustrate what it’s doing.

Link to video of ‘Designing the Human Mind’ talk.

Banjo brain surgery

Surely this must be the greatest headline for a BBC News story ever: Banjo Used in Brain Surgery.

Although the banjo wasn’t in the hands of the surgeons it was still an essential part of the operation. It was played by legendary Blue Grass musician Eddie Adcock who was having surgery to install a deep brain stimulation device to treat an essential tremor that had been affecting his playing.

The BBC News story has a video of the neurosurgery and the banjo playing, and it is pure genius. Probably the best thing you’ll see all year.

Essential tremor is a condition where there is a continuing deterioration in areas of the brain that control movement. This causes a tremor that usually appears when the person tries to act or move, although can lead to a ‘resting tremor’ that’s also present at other times.

Essential tremor is not Parkinson’s disease, which, while also associated with tremor, is a much more serious and disabling condition in many ways. There does seem to be a link though, as people with essential tremor are more likely to develop Parkinson’s, although this still only happens in the minority of cases.

However, deep brain stimulation can be used to treat the movement difficulties of both Parkinson’s and essential tremor. It involves sinking an electrode into the thalamus, a deep brain area that is part of the motor loop – a circuit that helps co-ordinate movement.

In fact, there are two parts to the motor loop – the direct and indirect pathway – an each play a complementary part in directing movement, and each of which needs to be balanced with itself and with each other. When damage to these circuits affects this balance, the result is that it causes too much activity one way, which causes a compensatory response the other, and so on.

Imagine two people, completely unaware of each other, trying to balance an uneven seesaw. The oscillations in the control system cause oscillations in movement, and this is what you can see in tremor.

DBS works by sending electrical impulses at a certain frequency into the thalamus to dampen down the oscillations. However, the oscillatory push-push cycle is not the same for everyone, and the best spot in the motor loop itself will also differ.

To get the best result the surgeons tweak the electrical pulse settings and try different areas.

To make sure it’s having the desired effect, the patient is awake and they ask them to move. When they see that they’ve hit the sweet spot and the pulses are in time, they know their job is done.

One of Eddie Adcock’s impairments is that he has tremor, but the main impact on his life is that it affects his banjo playing. So the most sensible thing to do is to tweak the system while he’s playing the banjo to optimise the effect for the thing that’s most important to him.

And that’s why a banjo was used in brain surgery.

Link to BBC video of ‘Banjo Used in Brain Surgery’.

2008-10-10 Spike activity

Quick links from the past week in mind and brain news:

Pfizer have been caught manipulating studies. Again. This time for the drug Neurontin. The New York Times has the full story.

Neurophilosophy discusses a new way of understanding the neurobiology of hallucinations.

An excellent Carl Zimmer article on the genetics of intelligence is available from Scientific American.

Neurotopia examines a case of a phantom erectile penis after sex reassignment surgery.

A wonderful quote from Nobel prize-winning neuroscientist Charles Sherrington starts an excellent piece on calcium imaging from Neurophilosophy.

The BPS Research Digest asks what is it about eye wiggling that helps people recover from trauma in an article on EMDR therapy.

Psychoanalytic Therapy Wins Backing. The New York Times reports on the recent meta-analysis that found that one year or more psychoanalytic therapy helps complex psychiatric patients.

NPR Radio has a short piece on research suggesting we may not be as good at multi-tasking as we think.

A new study [pdf] finding that 44% of children diagnosed with child bipolar disorder go on to have adult bipolar disorder is critiqued by Furious Seasons.

Advances in the History of Psychology has a short but interesting piece asking whatever happened to the male menopause?

A study that used electrodes implanted in the brain to record neural function during remembering is covered by PsyBlog.

Bogot√° bound

I’m off to Bogot√° to attend the annual conference of the Association of Colombian Psychiatry, so apologies if updates are a little erratic, but I shall try and report back with the highlights here.

I’ve been kindly invited to give a talk in a symposium on psychosis where I’ll look forward to getting a distinctly Colombian perspective on my interest in the neuropsychology of delusions.

Web therapy

Web Therapy is an incredibly funny and wonderfully made web series about a psychologist who does chaotic three-minute therapy sessions via webcam. It stars Lisa Kudrow, who plays the over-involved Fiona Wallace who can’t quite keep her personal issues out of the sessions.

It’s a really simple premise but is a very well observed satire on therapy and has some sublimely funny moments as Wallace tries to use the therapy sessions to justify her bad behaviour.

To be honest, the thought of Lisa Kudrow playing a psychologist kind of put me off, owing to a hang-over from Friends, but she plays quite a different character and does a fantastic job .

Link to Web Therapy (via BoingBoing).

The science of shrinking human heads

I’ve just found a wonderful article on how the Jivaro-Shuar, an indigenous people from the upper Amazon basin, shrink human heads after killing their enemies in battle. It’s from the medical journal Neurosurgery but it’s most fascinating for what it reveals about the complex customs and social relations that surround the practice.

The actual head shrinking is the end point in a raid on an enemies camp which apparently happens periodically, as they are almost always in revenge for being the victim of an earlier raid.

The victim of the revenge raid is not necessarily the perpetrator of the last attack. The new target is picked out by the shaman while under the influence of a hallucinogenic beverage called natéma (apparently a type of ayahuasca).

The significance of this vengeance cycle is remarkably similar to the one described by Jared Diamond in a New Yorker article on violence in the Handa people of New Guinea that we covered earlier this year.

The article does explain the process of shrinking heads, if ever you find yourself with a spare one, as well as the complex ritual and ceremonies that accompany the process and seem to pervade the whole life and identity of the Jivaro-Shuar.

Anyway, on to the head shrinking. After carefully removing the skin from and discarding the skull, a ritual pot is used to heat water.

As the water begins to grow warm, with a command, the headman leads the warriors in the rite: he seizes what remains of the head by its hair and, with the warriors‚Äô hands laid upon his hand grasping the victim‚Äôs head, he dips the head three times in the water. As he does this, he intones, ‚ÄúI dip the head in the boa‚Äôs water.‚Äù The warriors in turn respond, ‚ÄúHe is boiling the head.‚Äù The skin of the head is then placed in the vessel and allowed to steep for 15 to 20 minutes as the participants watch in silence. When the water reaches a boil, the vessel is removed from the fire, and the skin is recovered from the water with a stick and hung up on the tip of a spear to dry….

They retrieve the skin from its place on the spear and bind the hair on its scalp. Eyelet holes are pierced through the base of the neck, transforming the skin into a sort of pouch. The mouth is sewn shut with darts from below as the participants intone: “He is sewing.” The eyelids are sutured closed in a similar manner.

With the enemy’s skin now a pouch with a single mouth, the base of the neck, the skin is dried with heated sand and stones. The sand is heated on a round, hollow plate. The senior member of the party leads the warriors involved in the kill in scooping up the sand with a vessel and pouring it into the head, then shaking the head to drive the sand as far into the pouch as possible. This is repeated for hours as the participants repeat the chant, “I am pouring sand.” A large flat stone is likewise heated in the fire and used, held with the help of a leaf folded for the purpose, on the outside layer of the skin. The head is then complete.

Interestingly, once made, the heads are usually discarded as the significance lies in the process rather than the product.

It’s a completely fascinating article and really worth reading in full.

Link to article ‘The science of shrinking human heads’.
Link to PubMed entry for same.

The beauty algorithm and coding for the brain

The New York Times has a fascinating piece on some new software that automatically tweaks pictures of human faces to make them more attractive by reducing the concept of facial beauty to simple vector-based algorithms.

The image on the right is a ‘before and after’ picture of the software at work, and the researchers have a page for the project with many more examples and the full-text of the academic paper.

The researchers asked participants to rate the attractiveness of a series of faces and they then used software to calculate distances and directions between key facial landmarks.

By combining the attractiveness ratings and the landmark vectors they created a statistical model of which general facial attributes are most attractive. Their software allows new faces to be subtly altered to more closely approximate the general model of attractiveness.

I’m fascinated by the fact that software advances are increasingly taking advantage of the quirks of our mind and brain.

The MP3 format is perhaps the most well known, which allows audio files to be compressed because it takes advantage of a psychological effect called auditory masking where, when two sounds of certain frequencies are present, we can only perceive one.

The MP3 encoding algorithm simply scans sound files for times when auditory masking would eliminate the perception of one sound, and then actually eliminates the data from the file, thereby making it smaller.

Another wonderful idea is chroma subsampling used in jpg and digital video compression. It’s based on the finding that our visual system is less accurate at pinpointing colour differences than brightness differences.

Chroma subsampling takes advantage of this by storing colour information at a lower resolution than brightness information. For example, rather than storing separate colour information for every pixel, it will store it for every four. When we see the image, we often can’t tell the difference.

This is particularly true for moving images, and you’ll notice sometimes when you stop YouTube videos the colours seem to be fuzzy and bleed from where they’re supposed to be (have a look at this YouTube still I used on a recent post ) even though you hardly notice this when the video is playing.

These software advances wouldn’t have happened without the psychology research to find the bugs / features in human perception and it’s curious to think that these new developments build on both the digital and neural platforms.

What will be most interesting is if software starts to take advantage of cognitive features found only in certain members of the population (for example, some women have four types of colour receptor in the retina, rather than the usual three).

In other words, we might find that some important software advance will only work on some people (or rather, will be developed with only some people in mind), and so these people might be preferentially hired to work with certain applications.

If these applications become particularly high value (usually due to their use in the military or intelligence services), people might starting attempting to engineer themselves or others to have the uncommon attribute.

Sci-fi writers, start your engines.

Link to NYT piece ‘The Sum of Your Facial Parts’.
Link to researcher’s page with photos and full-text.

Ladies and gentlemen we’re floating in space

I just came across these two beautiful images in a paper by neuroscientist Marek Kubicki and colleagues on diffusion tensor imaging studies in schizophrenia.

DTI is a technique that using MRI scans to track how water moves throughout the brain. As water tends to move in one particular direction when its trapped inside nerve fibres, a technique called MRI tractography can be used to map out all the white matter ‘cabling’, separate from the rest of the brain.

I think the technique produces some of the most beautiful images in neuroscience. You get to see the brain’s connections, disconnected, and suspended in space.

Link to full-text of paper (see page 27 for images).
Link to PubMed entry for same.
Link to more DTI tractography images.

The museum of criminal brains

Today’s Nature has a fascinating one page article on the Turin anatomy museums that have the archives of the controversial founder of criminal psychology, Cesare Lombroso, who thought that deviant behaviour was imprinted in the face and brain from birth.

Lombroso had the theory that criminals were biologically defective, and that these defects – and hence criminality – could be found by measuring the body. This practice of interpreting someone’s character from their physical features is known as physiognomy and was in full swing before Lombroso started his studies but he was the first to apply it to criminology.

Unfortunately for the physiognomists, it’s impossible to reliably judge a person’s character from their physical appearance (although subtle statistical differences can be found when comparing the average of many people – such as with an iris patterning and personality study we reported on last year).

During his studies, however, Lombroso made a huge collection of brains, skulls, death masks, life masks, photos, measurements and even tattoos to try and prove his theory.

His other unshakeable theory held, ironically, that genius and madness were two sides of the same degenerate coin. In 1897, at the height of his fame, Lombroso travelled to Leo Tolstoy‘s village in Russia to gather living proof of the theory ‚Äî but the undisputed genius disappointed him by lacking the physical characteristics that Lombroso associated with madness. In turn, Tolstoy dismissed his visitor as “ingenuous and limited”, and later described Lombroso’s theories as a “misery of thought, of concept and of sensibility” (see Nature 409, 983; 2001). The great French novelist √âmile Zola levelled that Lombroso gathered proof selectively: “like all men with preconceived theses.”

The irrepressible Lombroso also had plenty of opponents back home in Turin ‚Äî most notably the neuroanatomist Carlo Giacomini, head of the University of Turin’s anatomy museum. In the 1880s, Giacomini had developed a ‘dry’ method for preserving brains based on mummification, which he put to lavish use. At least 950 of the resulting specimens are displayed in the Museum of Human Anatomy of the University of Turin, which reopened last year after renovation, having been closed for more than a century. Giacomini was a thorough, systematic scientist interested in individual variability in the gross anatomy of the brain. His analysis of the crevices, or sulci, of human brains suggested that there is sufficient variability among normal people to negate Lombroso’s theory that the size and shape of a brain dictate character. Typically, Lombroso ignored the data.

And, if I’m not mistaken, this page has a picture of Lombroso’s face, preserved in a jar. Can’t be sure though, as it’s in Italian, however, it does have loads of fascinating photos of the archive.

The article also notes that the another nearby museum has the collection of Luigi Rolando, a proto-neuropsychologist who attempted to related nervous system structure both to its biological function and partly to mind and behaviour.

One of the major landmarks in the brain is the central sulcus, which has the alternate name of ‘the Rolandic fissure’ or the ‘fissure of Rolando’ in his honour. Rather peculiarly, the Nature article uses a jarring mix of old and new and names it the ‘Rolando sulcus’ which seems to be virtually non-existent in the literature.

The only reference to this term in PubMed is from an obviously awkwardly translated French study which appeared earlier this year.

Anyway, a fascinating article and they look like some wonderful museums to visit if ever you’re in the beautiful Italian town of Turin.

Link to article.
Link to DOI entry.
Link to page in Italian with loads of photos.
Link to website for Cesare Lombroso Criminal Anthropology Museum.
Link to website of Luigi Rolando Human Anatomy Museum.

Everything I know about psychiatry, I learnt from heavy metal

If mental illness doesn’t exist, how come the dark forces of heavy metal know so much about it? Almost the whole range of psychopathology can be found on the cover of heavy metal albums.

You may never need buy a psychiatry textbook again.

Are you listening Thomaz Szasz?

Are you?

 

Continue reading “Everything I know about psychiatry, I learnt from heavy metal”

I have a hunch, but I’m just working out when to use it

The Boston Globe has an interesting piece on differing decision-making styles and how cognitive science is increasingly recognising the role of emotion in making choices.

It’s shoehorned into a slightly dubious Obama vs McCain premise, but it covers the important relationship between more conscious reflective forms of problem analysis, and more intuitive forms of approach.

Some of the most interesting research in this area has looked at how these systems interfere with each other.

One of my favourite studies used the Iowa Gambling Task, a card game where participants pick from four decks of cards that can either give them wins and losses. There are various version but a common variant is where two decks give a slight overall gain, while the other two give a slight overall loss.

It’s really hard to work out rationally, because there are just too many numbers to keep in your head, but after a while people tend to get an intuitive grasp of which are the best decks to stick with.

One particular study [full text], led by psychologist Cathryn Evans, found that people with a university education actually did worse on this task than people without one, presumably because they tended to over-apply futile rationalist strategies.

In terms of discussing the problem and ways of tackling it, a classic study by Jonathan Schooler found that getting people to talking about their problem-solving strategy actually made people worse at solving problems, particularly for ‘insight problems‘ where the solution lies in your ability to reframe the whole scenario – often in a counter-intuitive way.

Of course, some problems need a measured, thoughtful, analytical approach, whereas in some situations this interferes with the outcome. However, these are largely findings from lab tasks designed to isolate these types of problems whereas in the real world, problems come as a chaotic mix of both elements.

Knowing which strategy to apply is key, but then again, solving this problem is often equally as complex as solving the problem itself.

Link to Boston Globe article ‘The next decider’.

Viral brain cancer theory comes of age

The San Francisco Chronicle has a great article about Dr Charles Cobbs, a neurosurgeon who had the seemingly wacky idea that malignant brain tumours called gliomas might be caused by a viral infection. Initially dismissed, there is now growing evidence for his idea and how it might lead to better prevention and treatment for these usually fatal forms of brain cancer.

Gliomas are tumour that form from glial cells – non-neuronal brain cells that provide support, nutrition protection and some just-recognised roles in signalling.

As you might expect, they are an essential part of almost every part the brain and a malignant tumour which grows from glial cells can be fatal (without treatment, within about 3 months) as they are very difficult to remove and treat.

Cobbs had observed that his patients diagnosed with malignant glioma – an aggressive brain cancer that leaves victims with a two-year life expectancy – were mostly older, well-educated and from higher socioeconomic backgrounds. Their “hyper-hygienic” lifestyles had possibly left their immune systems susceptible to more common viruses, such as the human cytomegalovirus, or CMV, a herpes virus so ubiquitous that it infects 4 of 5 Americans.

During off-hours, and without formal research funding, Cobbs and a lab partner analyzed dozens of brain tumor samples: All of them were riddled with CMV. In 2002, the doctor published his novel finding in a leading medical journal Cancer Research where it was quickly dismissed by many of his peers. “I was left with a lot of self doubt,” said Cobbs, now 45. “My fear was that we’d done something incorrect. But now, my confidence is growing.”

In February, brain cancer researchers at Duke University Medical Center published the first peer-reviewed report that confirmed Cobbs’ discovery, followed by two reports from independent labs at the M.D. Anderson Cancer Center at University of Texas in Houston and the Karolinska Institute in Stockholm, Sweden. And this month, the National Brain Tumor Society is sponsoring a first-of-its-kind gathering in Boston of the world’s top virologists and glioma experts to examine the possible link between CMV and the deadly brain tumors that are diagnosed in 10,000 Americans every year.

The photos accompanying the piece are excellent by the way. The image I’ve used to illustrate this post is particularly impressive – click on it to see the full-size version which you need to get the full effect.

Nature also ran a piece about Cobbs last month owing to the publication of one of his studies in the same issue where he discovered one of key receptors on which the CMV virus has its action.

Unfortunately, I can’t read either as Nature’s Athens login system is currently broken [insert your own rant about open-access publishing here].

Link to SFChronicle article ‘Surgeon changes study of brain tumors’.

Deep brain optimism

A list of things that deep brain stimulation has been used to treat. DBS involves surgically implanting an electrode into the brain which is stimulated with a ‘pacemaker’ like device.

I’ve just been looking over the DBS literature and I was quite surprised to see that it has been used to try and treat just about anything you can think of.

Maybe someone should try it for over-optimistic repetitive surgery syndrome? Anyway, here’s the one’s I’ve found, if you know of any others, do send them in or add them to the comments.

Obesity

Writer’s cramp

Tremor

Depression

Parkinson’s disease

Epilepsy

Huntingdon’s disease

Addiction

Self-mutilation

Cluster headache

Tourette’s syndrome.

OCD

Early onset pantothenate kinase-associated neurodegeneration

Dystonia

Meige syndrome

Facial pain

An intuitive sense of humour

I’ve just discovered a delightful <a href="http://www.guardian.co.uk/world/2006/may/23/germany.features11
http://www.guardian.co.uk/film/2007/feb/10/comedy.television
“>article by English comedian Stewart Lee on why British people don¬¥t get German humour. He argues that the English language is full of ambiguities and that many jokes rely on resolving these in ways which are much less possible in the German language owing to the sentence structure.

It reminded me of a more recent article by another English comedian, Simon Pegg, on why Americans sometimes miss the irony in British humour. He argues that it’s not that they don’t understand irony, as the stereotype suggests, but that British people use it in situations which Americans are not familiar with, making it harder to understand as intentional humour.

Neither are scientific and both are really just opinion pieces, but it struck me that there are interesting parallels with the recent series of articles where professional magicians have collaborated with cognitive scientists to understand the consciousness and attention.

The gist was that stage magicians have developed a keen intuitive sense of how the human attentional system works in order to fool it, and cognitive scientists can benefit from this knowledge as it is eminently useful in designing experiments.

As far as I know, no similar collaboration has happened with professional comedians and cognitive scientists studying the psychology of humour, despite the fact that both the articles mentioned above seem to demonstrate an intuitive sense of the what makes things funny.

Richard Herring (a one-time comedic partner of Stewart Lee in a past double act) recently wrote a shorter piece on honing jokes that seemed also to capture some of this intuitive knowledge.

A beautifully chosen, unexpected adjective can transform a comedy routine into poetry, while the banal repetition of a common place noun can make that word, and consequently all language, suddenly appear ridiculous.

If you are a stand-up you can hone your material over successive performances, based on the audience response. Changing a single word or altering the pace or emphasis can make a previously failed witticism work.

You might be saying too much. Let the audience discover the consequences of a comedic notion themselves. A pause can be as effective as a paragraph of exposition.

Finally, remember that you will learn the most through trial and error.

Link to ‘Lost in translation’ on humour and the German language.
Link to article ‘What are you laughing at?’ on Americans and irony.
Link to article on honing a joke.